*facepalm* Thanks, I can't believe that wasn't my first thought as soon as I learned these instances were using iSCSI. That's almost certainly what is happening on this OCI instance, since the host adapter for its iSCSI transport is a ConnectX card. The fact that I was able to see similar behavior once on a machine booted from a local disk (in the A100 test I mentioned) is still confusing though. I'll update this thread if I can figure out a reliable way to reproduce that behavior. On Fri, Feb 7, 2025 at 1:01 PM Jason Gunthorpe <jgg@xxxxxxxx> wrote: > > On Fri, Feb 07, 2025 at 10:02:46AM -0600, Mitchell Augustin wrote: > > > Is it using iscsi/srp/nfs/etc for any filesystems? > > > > Yes, dev sda is using iSCSI: > > If you remove the driver that is providing transport for your > filesystem the system will hang like you showed. > > It can be done, but the process sequencing the load/unload has to be > entirely contained to a tmpfs so it doesn't become blocked on IO that > cannot complete. > > Jason -- Mitchell Augustin Software Engineer - Ubuntu Partner Engineering
